Oxidation Stress is Adaptative Reaction Inductor of Winter Wheat Plants

Hydrogen peroxide impact upon the activity of superoxide dismutase (SOD), catalase (CAT), development of lipid peroxidation processes (LP), photosynthetic pigment content and productivity in conditions of field experiment were studied for winter wheat varieties of different ecotypes, namely Stolychna, Polisska 90 – forest-steppe, and Scala-steppe. It was found that hydrogen peroxide action for 24 h induced LP activity, whereas antioxidative enzyme activity dropped at two varieties. Exception was the Stolychna plants that showed decrease in all indexes studied after treatment. In the next phase of ontogenesis (flowering), however, SOD activity increased both in the plants of Polisska 90 and Scala, while CAT and LP activities were close to control in all plants. The data suggest that treatment by hydrogen peroxide stimulated the formation of general unspecific resistance of plants and increased the grain productivity of winter wheat varieties studied

Antifungal properties of hypericin, hypericin tetrasulphonic acid and fagopyrin on pathogenic fungi and spoilage yeasts

Context: The role of hypericin-mediated photodynamic antimicrobial properties on pathogenic fungi and photodynamic therapy for human cancer cells is known. Antifungal properties of Hypericum perforatum L. (Hypericaceae) and Fagopyrum esculentum Moench. (Polygonaceae) extracts were also studied. The different polarities of solvents can cause complication in the identification of antifungal effects of separate biologically active compounds. In recent experimental work, we compared antifungal properties of purified hypericin, hypericin tetrasulphonic acid (hypericin + S) and fagopyrin, which is analogue of hypericin. Objective: The antifungal properties of aromatic polyketide derivatives such as hypericin, hypericin + S and fagopyrin on the selected pathogenic fungi and spoilage yeasts have been studied. Materials and methods: The antifungal properties of hypericin, hypericin + S and fagopyrin were determined using the broth microdilution method against a set of pathogenic fungi and spoilage yeasts including: Microsporum canis, Trichophyton rubrum, Fusarium oxysporum, Exophiala dermatitidis, Candida albicans, Kluyveromyces marxianus, Pichia fermentans and Saccharomyces cerevisiae. The tested concentrations of hypericin, hypericin + S and fagopyrin ranged from 750 to 0.011 μg/mL and MIC values were evaluated after 48 h incubation at 30 °C. Results: The results confirm different antifungal properties of hypericin, hypericin + S and fagopyrin on the selected pathogenic fungi and spoilage yeasts. For pathogenic fungi, the minimum inhibitory concentrations of hypericin ranged 0.18–46.9 μg/mL, hypericin + S 0.18–750 μg/mL and fagopyrin 11.7–46.9 μg/mL. For spoilage yeasts, the MICs of hypericin and hypericin + S ranged 0.18–46.9 and 0.011–0.73 μg/mL, respectively. Discussion and conclusion: The results obtained herein indicate that various chemical structures of hypericin, hypericin + S and fagopyrin can develop different antifungal properties